At the northernmost end of Manhattan Island, in the shadow of one of the city’s oldest forests, is the last Irish pub in a neighborhood once dotted with nearly a hundred of them. The story of the Liffy II begins in the early nineteen-sixties, when an Irishman called Sean Cassidy took over a ground-floor room from an Italian whose name has been lost to history. Cassidy opened a small tavern and called it Innisfree, after a W. B. Yeats poem about an uninhabited island, which is inscribed in the Irish passport. In 1968, Cassidy passed the reins to Andy Carney, a thirty-three-year-old former bus driver from Ballaghaderreen (current population 1,808); Carney sold the business a few years later, but stayed on as a bartender. He is there to this day, pouring what must be his millionth Guinness, and has never been seen without a necktie. In the late seventies, the bar came under the ownership of the proprietor of a now defunct Bronx alehouse called the Liffy, like the river. He rechristened Innisfree as the Liffy II, and in 1999 it was purchased by a Dubliner named Kirby Mannix, who has been running the place ever since. On a recent Wednesday afternoon, Mannix dropped by while Carney was on duty, and they spoke of times past. “Every bar around here was a bucket of blood,” Mannix said. “You always got somebody coming through the door thinking they’re Mike Tyson.” An eavesdropping local brought up the subject of the baseball bat behind the bar. “Andy had no problem with the Peacemaker,” Mannix said, smiling warmly at Carney, who denied ever having clubbed a paying customer. “Tell the truth, Andy!” Mannix teased, and Carney shuffled off to the other end of the bar. (5009 Broadway, near 213th St. 212-544-7669.)♦